Dithiophosphate esters as insecticides



Patented May 6, 1952 DITHIOPHOSPHATE ESTERS AS INSECTICIDES Edwin O. Hook, Old Greenwich, Conn., and Philip ,H. Moss, Nederland, Tex., assignors to AmericanCyanamid Company, New York, N. Y., a

corporation of'Maine No Drawing. Application March 26; 1948, Serial N0. 17,393

4 Claims. (Cl. 167-22) The present invention relates to insecticides, andmore, particularly to insecticidal compositions containingas a toxic ingredient a dithiophosphate ester of the general formula in which R1 and R2 are members of the group consisting of aliphatic hydrocarbon radicals and halflgen-substituted aliphatic hydrocarbon radicals, R3 represents an aliphatic hydrocarbon radi- The esters utilized in this invention may be prepared by reacting together an aliphatic alcohol or'mercaptan, an aldehyde, and a dialkyl ester or dithiophosphoric acid. A typical reaction in which tertiary butyl mercaptan, formaldehyde,

. and diethyl dithiophosphoric acid are reacted together to' produce S-tert.-butylmercaptomethyl 0,0-diethyl dithiophosphate may be illustrated as follows:

Aldehydes which may be utilized in the preparation of the insecticidal compounds include formaldehyde, acetaldehyde, propionic aldehyde. butyric aldehyde, cinnamlc aldehyde, benzaldehyde, and the like. For instance, in the above general formula, when acetaldehyde is employed in the process the symbol Z becomes methyl, and when benzaldehyde is employed Z becomes the phenyl radical.

These compounds are high-boilingliquidssubstantially insoluble in water, butsoluble in many organic liquids including the ketones, namely, acetone, cyclohexanone, isophorone, methyl ethyl ketone, and the like; the monohydric aliphatic alcohols; various esters, namely, the acetates, phthalates, abietates, fumarates, maleates, and the-like; ether alcohols such as the polyethylene glycol's; ketone-alcohols such as diacetone .alcohol; polymethylated naphthalenes; animal and vegetable oils, and petroleum oils.

The term carrier as used hereinafter means a vehicle used to transport the toxic agent. to. the insect to be destroyed. Such carriers maybe solids, liquids, or gases. For instance, solldssuch as various clays, talcs, diatomaceous earths, iullers earths, pyrophyllites, cellulosic sheets, sawdust, and the like, may carry the toxic agent through absorption or adsorption with or without the assistance of a'solvent ornon-solvent carrier. Liquid carriers may be classed as'solventstand non-solvents for the organic dithiophosphates. The non-solvents will, of course, require a minor proportion of an emulsification agent to thoroughly distribute the toxic agent through the carrier. Under such circumstances any wellknown inert emulsification agent may be used in, say, a proportion of from 1% to 10%, such as the polyethylene glycol, sorbitol, mannitol, and pentaerythritol laurates. Such solvent carriers maybe the phthalate, fumarate, maleate, acetate, and naphthenate esters, the monohydric aliphatic alcohols, the polyethylene glycols. ketones, aromatic hydrocarbons such as benzene, toluene, xylene, and the polymethylated naphthalenes, ketone-alcohols, animal and vegetable oils such as the soybean, cottonseed, linseed, peanut, tallow, and the partial and-completely hydrogenated products, and "petroleum hydrocarbons such as petroleum ether, kerosene, "and the refined spray oils or mixtures thereof. Insomecases a combination of solvent and non solvent carrier-may be used, the solvent and non-solvent Zbeing miscible. Sincesome of the organic dithiophosphates in controlling various insects is illustrated Per- Compound Dilution cent Kill S-tert.-butylmercaptomethyl 0,0-diethyl dl- 1l00,000 100.

thiophosphate. S-tert.-butylmercaptomethyl 0,0-diethyl dil500,000- 98.3

thiophosphate. S-tert.-butylmercaptomethyl 0,0-diethyl di- 14,000,000. 72.0 thiophosphate. S-tert.-butylmercaptornethyl 0,0-bls (2-chlorol500,000 100.

ethyl) dithiophosphate. S-tert.-butylmercaptomethyl 0,0-dimethy1 olill0,000.. 100.

thiophosphatc. S-tert.-butylmercaptomethyl 0,0-dimcthyl dil100,000-. 97.0

' thiophosphate.

S-tert.-butylmercaptomethyl 0,0-di-n-propyl 1100,000 100. dithiophosphate. S-tert.-buty1mercaptomethyl 0,0di-n-propyl l500,000 83.5

dithiophosphate. S-tert.-butylmercaptomethy10,0-(ii-n-buty1 di-. 140,000... 96.2

thiophosphate. S-sec.-amylmercaptomethyl 0,0-cliethyl dithiol-l0,000 .100.

phosphate. S-sec.-amylmercaptomethyl 0,0-diethyld1thio- 1--lO0,000 99.6

phosphate; S-tert.-heptylmercaptomethyl 0,0-d1ethyl dll-10,000.. 100.

'thiophosphate. S-tert.-heptylmercaptomethyl 0,0-d1ethyl dill00,000 99.0

thiophosphate. S-tert.-heptylmercaptomethyi 0,0-d1ethyl di- 1500,000 68.0

thiophosphate. S-tert.-heptylmercaptomethyl 0,0-bis(2-cl|1oro- 1--10,000. 99.0

ethyl) dithiophosphate. S-tert.-heptylmercaptomethyl 0,0-bis (2-chlorol100,000 83. 0

ethyl) dithiophosphate). S n-octylmercaptomethyl 0,0- liethyl dithiol-10,000 100.

phosphate. S-n-octylmercaptomethyl 0,0'diethy1 dithiol-l00,000.. 76.3

phosphate. S-tert.-dodecylmercaptomethyl 0,0-dimethyl 140,000. 96. 0 dithiophosphate. S-tert.-dodecylmercaptomethyl 0,0-diethyl dill0,000; 97.0

thiophosphato. S-etyhogrymethyl 0,0-diisopr0pyl dithiophos- 1-l0,000 94.0

p a e. S-tert-butoxymethyl 0,0- li-n-propyl dithiol10,000 99.9

phosphate. S-ngntwxymethyl 0,0-diethyl dithiophosll0,000.. 79.5

p a e. S-tert.-but0xymethyl 0,0 -diethyl dithiophos 1-10,000. 84.0

' ate. S-n-butoxymethyl 0,0-bis (2-chlorocthyl) dil-10,000 99.0

thiophosphatc.

Trz'bolium ccnfusum.-80-100% kill in 24 hours with S-tert.-butylmercaptomethyl 0,0-diethyl dithiophosphate, 3 tert. butylmercaptomethyl 0,0-bis(2 -ch1oroethyl) dithiophosphate, S-tert.- butylmercaptomethyl 0,0-di-n-propyl dithiophosphate, S-sec-amylmercaptomethyl 0,0-

diethyl dithiophosphate, S-tert.-heptylnie rcapt0- H methyl 0,0-diethyl dithiophosphate, S-tert.-

S-tert-butoxymethyl 0,0-di-n-propyl dithiophosphate in concentrations of 0.1-1.0% adsorbed on solid carriers such as talc, pyrophyllite, and attapulgus clay.

The dithiophosphate esters may also be employed in controlling the green peach aphid, pea aphid, chrysanthemum aphid, greenhouse thrips, California red scale, citrus red spider, greenhouse red spider, milkweed bug. mealy bug, sow bug, Southern army worm, yellow fever mosquito, malarial mosquito, Mexican bean beetle, and black carpet beetle.

These new insecticidal compounds may also be used in combination with insecticides such as lead arsenate, nicotine, rotenone, pyrethrum, benzene hexachloride, 1,1 di(p-chlorophenyl)-2,2,2-trichloroethane, dodecyl thiocyanate, phenothiazine, and the like; with fungicides such as sulfur,

various copper compounds, mercury salts, and,

the like; and with various types of plant foods and fertilizers.

Further details regarding the preparation of the esters utilized in this invention are given in copending application Serial No. 17,396, filed concurrently herewith and now Patent No. 2,586,655.

While the invention has been described with particular reference to specific embodiments, it is to be understood that it is not to be limited thereto, but is to be construed broadly and restricted solely by the scope of the appended claims.

We claim:

1. An insecticidal composition containing as a toxic ingredient S-tert.-butylmercaptomethyl 0,0-diethyl dithiophosphate,-and a carrier.

2. An insecticidal composition containing as a toxic ingredient S-tert.-butylmercaptomethyl 0,0-bis(2-chloroethyl) dithiophosphate, and a carrier.

methyl 0,0-di-n-propyldithiophosphate, s-tert.-

butylmercaptomethyl .0,0-diethy1 dithiophosphate, S-tert.-heptylmercaptomethyl O,O- diethyl dithiophosphate, S tert. butylmercaptomethyl 0,0 bis(2 chloroethyDdithiophosphate, and

3. An insecticidal composition containing as a toxic ingredient S-tert.-butylmercaptomethyl 0,0-di-n-propyl dithiophosphate, and a carrier.

4. An insecticidal composition containing as a toxic ingredient a dithiophosphate ester of the general formula V in which R1 and R2 are members of .the: group consisting of alkyl and chlor-substituted alkyl radicals having not more than four carbon atoms, R3 represents an aliphatic hydrocarbon radical, X represents a member of the group consisting of sulfur and oxygen, and a carrier.

EDWIN O. HOOK.

PHILIP H. MOSS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,939,951 Buchanan Dec. 19. 1933 2,063,629 Salzberg et a1. Dec. 8. 1936 

4. AN INSECTICIDAL COMPOSITION CONTAINING AS A TOXIC INGREDIENT A DITHIOPHOSPHATE ESTER OF THE GENERAL FORMULA 